Mine cable cutter



m May 20, 1947. R,`TEMP1 E,JR 2,420,987

MINE CABLE CUTTER Filed DeC. 51, 1941 2 Sheets-Sheet l zo f' Il IIZE INVENTOR.

WW, 7/ BY, b/IM ,L/MMM -klg ATTORNEY@ May 20, 1947. R, TEMPLE, JR 2,420,987

MINE CABLE CUTTER Filed Dec. 3l, 1941 2 Sheets-Sheet 2 zi 'l 4f Z3 23 7 3Q .I %9 f1,2 16m@ Si a ZZ 13 f3 38\v| Bi 12 \f4 3f 4 f 31 ,/Z ff-23 da //sz o I //Z8 Il /27 .3-/\ d /4 if /47 /J zv A JZ l, Ji y? M ATTORNEYS.

Patented May 20, 1947 Unire MINE CABLE CUTTER Robert Temple,..ir., Pittsburghla., assignony mesne assignments,` to TempleVelocity. Equip- .'rnent, nc.,la`corporation .Delaware ApplicationDec/ember 31, 19.4.1,- `aerial.l\l0. 425,027 17 Claims. @Lilli-221) -This invention relates Ato cable cutters, and more .particularly to devices for cutting .the cables by which explosive mines are anchored in oceans and other bodies of water.

As a part of naval warfare .light draft ships sail over mined waters in an endeavor to locate and explode the mines that have been planted there by the enemy. After awar is over the same practicemay be followed in .destroying mines .that may have been planted by the same country that is clearingawaythe iield. The ships or mine sweepers engage'din 4.this work generally make use of cables that are towed along behind or between them for. pulling the mines from their anchors or for exploding them.

It is among the objects of .this invention to provide mine sweeping apparatus which cuts the cables that anchor the minesunder water so .that they. will rise to the surface where they can be exploded by gun nre, which is operated by `the mine cables themselves, which is dependable. in operation, which can be used over .and over, which maintains itself in operating position, which is guarded from accidental operation, and whichcanbe used effectively in groups.

In accordance with this invention a cutter frame is provided with a slidably mounted piston andi knife that are connected together. The frame is adapted'tobe connected to a sweep line towed.` through the waterby a ship, and is so formed andmounted on the lineas tomaintain the knife substantiallyhoriaontal and at right angles to `the sweep line. The knife. has a recess in its front side for receiving amine` anchoring cable which 4is cut off against the frame. when the knifeis actuated. 'IlfieactuaQtingY means cornprises an explosive .cartridge and a spring pressed firing pin that is released by a trigger which is so connected to the. knife that when a mine .cable enters the recess in the knife it movesthe trigge-r and thereby `res the explosive charge. The frame is provided with a vane or n that maintains the frame 4and knife substantially horizontal while it is being towed through the water by the sweep line. i The end of the knife preferablyprojects from the end of the frame and is protected by a guard member that falls away from the frame when the knife cuts the cable so that the guard will not hook onto the next mine cable or prevent it from reaching an operable cuttingdevice fastened to the same sweep line farther away from the ship. Thecartridgeis held in a tubular member mounted in stationary position in the frame .and projecting into the lpiston which is hollow. Thetrigger is held in cocked position 2 by a ,Sheanpinwhns shearedo when tbetrisser A,is struckhardenough, suchs by a .mine cable.

.The nreferredembodment of .the .invention is illustrated in .the accompanying .drawings in whichFig. .1 isa...horizontal section A through my cable cutter. attached.. toa sweep 1ine;...Fig. 2 is an end view .thereof Fig. 3 .is a transverse section takenon the lineIII-,IIIJof Fig. V1; Fig. 4 is a fragmentary longitudinalsection taken on the line IV-IVof Eig. 3; .F.ig. 5 isA an elevation ofjthe rear side` of thecutter; and Eig.. 6 is a longitudinal section taken on the line VI-VI of Fig. 1.

Referringto .the drawings a metal frame I. is provided with alongitudinally Lextending guidewayl .inlwhich a hollow piston is slidably rnbunted. .Thepiston has an integraLpin 4 projecting from one' side into an opening in the inner end of ablade or"knife5 that isslidable along one side/of the guideway in parallel grooves' 5 formed in theframe. The other end of the knife projects fron'li'the end of the frame through a slot I therein. `'Iheiraineis made in two principallpartsia body 8 anda cover platen!) (Fg. `6) that is` held againstthe side of the gudeway opposite to thehknife 1by vscrews Ill and II. The cover plate' also extends across one end of the frameand contains the Vslot 'l throughwhichjthe knifeextends. W"

This cuttingdevice is'designed tobe towed by a ship through'thewater inthe direction .oi 'the arrow in Fig-lfbyineans' of asweep line I2 to which it'is attached. QAlthou'gh the cutter lmay be connected to the line fin various ways, it ispreferredto provide the end of frame I 'adjacent the projecting endvof the-knife with a passage I3 through which a sweepline canextend. One half `ci thislpas'sageis in ,the `frame. body 8 and thedother half hin the endportion .of plate. 9 'so thatdwrhen .the plate is removed from the body the passage is opened for ,the reception of the sweep line. The cutter is held in any desired position along such a line by means of removable collars .-l clamped onthe line infengagement'with opposite sides of the frame. To maintain the device substantially horizontal as it"is beingl drawn through .thewater theend of the frame farthest from the sweep Aline is provided with a vanebr fin i5 preferably 'integral with the frame. f PaS- sage AI3 is' somewhat larger than line `I24 andis provided at itsends with 4outwardly Aflaring yside walls engaged by conical thrust bearings I6 ,t hat are held in 1c lace,.y bybollarswlli. Consequently, sweep'line' I2 is free'to turn in passage I3 without 3 rotating the cutter, and the cutter therefore maintains itself in cutting position.

As shown in Fig. l, the projecting end of knife 5 has a recess 2| in its front side for receiving or hooking onto a mine-anchoring cable 22 as the cutter is drawn through the water. By forcefully moving the knife toward the opposite end of the fra-me as soon as the cable enters recess 2i, the cable is sheared off against the adjacent end of the frame. To maintain a satisfactory cutting surface on the frame it is preferred to fasten a slotted hardened steel plate 23 to the end of the frame, as shown in Fig. 6.

Another feature of this invention is that the cutting movement of the knife is produced by means of an explosive charge. For this purpose a cartridge-retaining member is removably mounted in the frame which is provided with a recess 25 at the inner' end of guideway 2. This recess is wider than the guideway, whereby shoulders 26 are formed'at opposite sides of the frame as shown in Fig. 1. The cartridge-retaining member consists of a tubular portion 21 in which a cartridge is placed and that projects into the hollow piston 3 with which it has a sliding t, and a iiange 28 at its outer end that engages shoulders 26. The flange is held tightly against the shoulders by a breech block 29 snugly tted in recess 25 between flange 28 and the opposite end of the recess. The breech block is held in place by the frame cover plate 9 and the knife, and also by a lock screw 30 threaded in the frame.

The breech 'block contains a central bore 32 in which a firing pin 33 is slidably mounted. One end of the bore is reduced in siZe and it is through this small passage that the tip of the firing pin is projected to discharge a cartridge held in the cartridge member. A coil spring 3| encircles the shank of the firing pin between a head 34 near its inner end and a screw plug 35 threaded in the breech block and in which the outer end of the firing pin is slidably mounted. The outer end of the ring pin is provided with a threaded opening 36 (Fig. 3) for receiving the threaded end of 45 a tool, not shown, by .vhich the pin can be pulled out through the screw plug to compress the coil spring and thus cock the device. The pin is held in cocked position by means of a dog 3'! (Fig. 3)

pivotally mounted on the end of the breech block 50 and having an arcuate end adapted to be swung manually into an annular groove 38 in the projecting end of the pin. The opposite end of the dog is adapted to project beyond the side of the breech block and cess 2| as shown in Figs. 3 and 4.

The chance of accidentally releasing the ring pin is minimized by a shear pin 4G slidably mounted in a small bore in the breech block beside firing against the bottom of dog 3l' by a spring 4| compressed between the pin and a screw plug 42 in the opposite end of the small bore. When the dog is swung into ring pin retaining position, spring 4 l5 is provided which is so connected to the knife that it is actuated by the mine cable 22 that is to be cut. The trigger is in the form of a lever having a laterally projecting boss iii between its ends that rotatably interlocks with a notch in the inner wall of knife recess 2|. This portion of the recess wall projects somewhat so as to form a fulcrum for the trigger. When the device is ready to be fired the laterally projecting end of dog 37 engages the side of the inner end of the trigger which is rocked on its fulcrum so that its outer end is spaced from the back of knife recess 2i across which it projects. Consequently, when the mine cable enters the recess it pushes the outer end of the trigger back against the knife and thus swings the inner end of the trigger forward, thereby causing the dog to cut olf shear pin il and to rotate far enough to release the firing pin. The firing pin discharges the cartridge and the force of the explosion moves piston 3 along guideway 2 toward the opposite end of the frame. Pressure is allowed to build up in the piston before it starts to move because the piston can not move until the pressure is great enough to cause it to shear off another shear pin fr? extending entirely through the frame and pistcn in holes provided for that purpose. As the piston is suddenly forced toward the end of the frame it pulls the outer end of the knife toward the frame, whereby the knife cuts off cable 22 against plate 23 attached to the frame.

To prevent the projecting end of the knife from being knocked against something, such as the side of the boat when the cutter is being lowered into the water, and thereby shearing off the piston shear pin 47, the end of the knife is protected by a surrounding guard member 48 held thereon by the frictional engagement of screws 49 threaded in the guard. The guard may be shaped to help guide a cable into the knife recess, as shown in Fig. l. When the cartridge is exploded and the knife drawn inwardly of the frame and out of the guard, the released guard falls away from the frame so that it will not hook onto the neXt mine cable and prevent it from reaching another cutter farther back along the sweep line. The knife guard is connected by a chain 5E) to the n I5 so that it will not be lost when released from the knife. The knife itself is drawn far enough into th'e frame to prevent its outer end catching on an uncut cable. The knife also may be provided with a beveled edge to assure the cable sliding across the into the inner end of knife re- 55 front end of the knife' A strong enough explosive charge is contained in each cartridge to cause the cutting of the largest mine cable that the cutter will accommodate. In such cases most of the energy in pin bore 32 The shear pin is pressed 60 the charge is utilized in cutting the cable so that the piston does not strike the end wall of the guideway with undue force. However, sometimes smaller cables are encountered and there is therefore danger that the piston will strike 4| forces the shear pin outwardly into a Small 35 the end wall of the guideway so forcefully as to depressio-n 43 in the bottom of the dog and thereby holds the dog in position until enough force is applied to its projecting end to shear off the shear pin. It will be seen that the shear pin operates automatically to hold the is swung into firing pin retaining position, and that the same shear pin can be used several times before it becomes too short and requires replacement.

To release the dog from the firing pin a trigger 75 dog whenever it in shearing Off cause damage. To avoid this a rather heavy shear pin 5l is disposed in the frame near the outer end of the guideway across which it extends. The piston is slowed down considerably this pin and therefore does not strike the frame too hard. Furthermore, it is preferred to make this pin of a soft material, such as copper, which crushes and acts as a cushion when forced against the frame by the piston. Bleed holes 52 (Fig. 6) are formed in the cover. plate to facilitate escape of Vwaterfrcm behind the piston whenthe cartridge is fired.

To load and cock this cuttertheA cover plate 9 must first be removed from the frame body 8v so that pistont, the cartridge-retaining memberrand breechblock 2Q can likewise be withdrawn from the frame. .A cartridge is inserted in tubular member 2l which is then inserted in the hollow piston and the assemblyis returned to the frame. A pinll on the piston must project into the opening-provided for it in the knife which is projecting from the end of the frame, as shown infFig. 1. rhe firing pin 33 isthen pulled back and held by dog 31 and the block replaced in the frame with the projecting end ofthe dog against the front side of the inner endoftrigger-45 ready to bereleased when the outer end of the trigger is struck -bya'mine cable. The cover plate is then screwed back onto theframe body to hold the pistonl in place.

According to the provisions of the. patent statutes, I have explained the principle and` construction Vof my invention and have illustrated and described what now consider to represent its best embodiment. Howeven desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and-de scribed.

I claim:

1. A mine cable cutter comprising a frame provided with a longitudinally extending guideway, a pistonslidably mounted therein, a knife slidably mounted in said frame and connected to the piston, one end of said knife projecting from an end of the frame and being provided in its side with a recess for receiving a cable to cut it against the frame, means for holding a cartridge adjacent the piston, a spring pressed firing Ypin for the cartridge, means operable by a cable entering said recess for releasing the ring pin, and a guard provided with an opening for the projecting end of the knife, the wall of said opening in said guard frictionally engaging the knife whereby when the knife cuts a cable the knife is withdrawn from said opening and the guard falls away from the frame.

2. A mine cable cutter comprising a frame provided with a guideway, a hollow piston slidably mounted therein, a knife slidably mounted in said frame and connected to the piston, said knife being provided with a cable-receiving and cutting recess, a ,tubular cartridge-retaining member mounted Yin fixed position in said frame and projecting into said piston, a spring pressed firing pin for the cartridge, and means operable by e, cable entering said recess for releasing the firing pin.

3. A mine cable cutter comprising a frame provided with a guideway, a hollow piston slidably mounted therein, a knife slidably` mounted in said frame and connected to the piston, said knife being provided with a cable-receiving and cutting recess, a tubular cartridge-retaining member extending into said piston and provided at its outer end with a flange, said frame being provided at one end of the guideway with a recess in which said flange is disposed, said frame recess being wider than the guideway and forming therewith shoulders against which said flange bears, a breech' block mounted in-said frame recess in engagement with the outer side of said flange, said blockhaving a passage therethrough, a spring pressed `firing pin slidably mounted insaid passage for discharging a cartridge in said tubularmember, and means operable by ,acable entering said knife recessfor releasing the firingpin.

4. A minecablecutter comprising Va'frame .provided with a guideway, a piston slidably mounted therein, aknifeslidably mounted insaid frame and connected to the piston, said .knife being provided withV a cable-receiving and cutting recess, means for holding a cartridgeadjacent the piston, a spring pressed firing pin for the cartridge, a .pivoted dog Afor ho-ldingthe firing pin in cocked position, a shear pin for holdingthe dog in cocking position, and a trigger operable by a cable enteringsaid recess for causing said dog to shear off the shear pin 4and thereby release the ring pin.

5. A mine cable cutter comprisinga frame provided with a guideway, a piston slidably mounted therein, a knife slidably mounted in said frame and connected tothe piston, said knife being provided with `a cable-receiving and cutting recess, means for holding a cartridge adjacent the piston, a spring pressed firing pin for the `cartridge, a pivoted dog for holding the firing pin in cocked position, .a shear pin, aspring pressing the shear pin toward one face of the dog, said face being provided with a recess for receiving the end of the shear pin when the dog is in cock-ing position, and a trigger operable b-y a cable entering said cable-receiving recess for causing said dog to shear off the shear pin Vand thereby release the firing pin.

6. .A `mine cable cutter comprising-aframe provided with a guideway, a piston slidably mounted therein, .a knife slidably mounted in said frame and connected to the piston, said knife being provided with a cable-receiving and cutting recess, means forl holding a cartridge adjacent thepiston, a spring pressed firing pin for the cartridge, a dog for holding the firing pin in cocked position and provided with a lateral projection, and a trigger pivotally connected between its endsto said knife, one end -of the trigger being adapted to be engaged by a mine cable and swung backwardly so as to swing its opposite end-forward, and said opposite end being positioned to actuate said dog and thereby release the ringpin.

7. A mine cable cutter comprising a frame provided with a longitudinally extending guideway, a piston slidably mounted therein, a knife slidably mounted in said frame at one side of the guideway and projecting from the end of the frame, means connecting the knife to the side of the piston, the projecting end of the knife having a recess in its side for receiving a cable to cut it against the end of the frame, explosivering means adjacent said piston for driving the piston, and means in said knife recess actuatable by-a cable entering the recess for operating said explosive-firing means.

8. A mine cable cutter comprising a frame provided with a guideway, a piston slidably mounted therein, a knife slidably mounted in said frame and connected to the piston, said knife being provided with a cable-receiving-and cutting recess, means for holding a cartridge adjacent the piston, a spring pressed firing pin for the cartridge, means Operable by a cable entering said recess for releasing the firing pin, and a shear pin extending across said guideway for cushioning the impact of the piston against the end wall of the guideway when the cartridge explodes.

9, A mine-cable cuttercomprising a frame provided wtha guideway, a piston slidably mounted therein, a knife slidably mounted in said frame and connected to the piston, said knife being provided with a cable-receiving and cutting recess, means for holding a cartridge adjacent the piston, a spring pressed ring pin for the cartridge, means operable by a cable entering said recess for releasing the firing pin, one end of the frame being provided with a passage for loosely receiving a sweep line, bearings rigidly disposed on said line and projecting into the ends of said passage and engaging the wall thereof, and a n at the other end of the frame for holding it substantially horizontal while being towed through water by the sweep line regardless of twisting of the line.

10. A mine cable cutter comprising a frame provided with a guideway, a piston slidably mounted therein, a knife slidably mounted in said frame and connected to the piston, said knife being provided with a cable-receiving and cutting recess, means for holding a cartridge adjacent the piston, a spring pressed firing pin for the cartridge, means operable by a cable entering said recess for releasing the ring pin, and a shear pin of soft metal extending across said Y guideway for cushioning the impact of the pistonagainst the end wall of the guideway when the cartridge explodes.

l1. A mine cable cutter comprising a substantially horizontal frame formed at its front end for attachment to a sweep line extending transversely thereof, said frame being provided with a guideway extending longitudinally thereof, a piston slidably mountedin the guideway, a knife slidably mounted in said frame beside the piston and connected thereto, the front end of said knife projecting beyond the front end of the frame and being provided in its side with a recess for receiving a mine cable to cut it against said end of the frame, means for holding a cartridge adjacent the piston, a spring-pressed ring pin for the cartridge, and means operable by a cable entering said knife recess for releasing the ring pin.

12. A mine cable cutter comprising a frame provided with a longitudinally extending guideway, a piston slidably mounted therein and having a laterally projecting boss, a knife slidably mounted in said frame at one side of the guideway and projecting from the end of the frame, the inner end of the knife having an opening receiving said boss, the projecting end of the knife having a recess in its side for receiving a cable to cut it against the end of the frame, explosive-firing means adjacent said piston for driving the piston, and means in said knife recess actuatable by a cable entering the recess for operating said explosive-firing means.

13. A mine cable cutter comprising a frame provided with a longitudinally extending guideway, a piston slidably mounted therein, a knife slidably mounted in said frame at one side of the guideway and projecting from the end of the frame, means connecting the knife to the side of the piston, the projecting end of the knife having a recess in its side for receiving a cable to cut it against the end of the frame, explosive-firing means adjacent said piston for driving the piston, the inner wall of said knife recess having a notch therein, an elongated trigger in the recess having a boss between its ends projecting into and interlocking with said notch to make the trigger tiltable longitudinally, one end of the trigger being adapted to be engaged by a mine cable and swung backwardly so as to swing its opposite end forward, and said opposite end being adapted when swung forward to operate said explosive-ring means.

14. A tether-cutting device, comprising a body, a severing element longitudinally slidable in said body, said element having an arcuate cutting portion that projects outside and faces toward said body when said device is set and is retracted into said body when said device is tripped to cooperate shear-wise with said body, a breech in said body, a spring-actuated ring pin in said breech, a sear engageable with said firing pin to hold said pin in cocked position, a trigger rockably mounted in said element adjacent said cutting portion whereby an object contacting said trigger will lie in the path of said cutting portion as said element is retracted into said body, said trigger being engageable with said sear to release said firing pin when said trigger is so contacted, and a piston slidable in said body and connected to said severing element, said piston having in it an explosivecharge chamber closed at one end and disposed with its other end abutting said breech when said severing element is projected, to position a charge in said chamber to be fired by said firing pin when said pin is released, whereby i'lring of said charge drives said piston away from said breech, which retracts said severing element into said body and severs an object that contacts said trigger.

15. A tether-cutting device comprising a body, a severing element reciprocally extending into said body, said element having a cutting portion that projects outside and faces toward said body when said element is set and is reciprocated into said body when said element is tripped to cooperate shear-wise with said body, trigger means trippable by a tether between said cutting portion and said body, an explosion operated means responsive to tripping of said trigger means to retract said cutting portion of said element into said body, and a tether guide detachably securable to said element while said element is in projecting position.

16. A tether-cutting device comprising a body, a severing element reciprocally extending into said body, said element having a cutting portion that projects outside and faces toward said body when said element is set and is reciprocated into said body when said element is tripped to cooperate shear-wise with said body, trigger means trippable by a tether between said cutting portion and said body, an explosion operated means responsive to tripping of said trigger means to retract said cutting portion of said element into said body, a tether guide detachably securable to said element while said element is in projecting position, and loss-preventing means securing said tether guide to said body when said guide is detached from said element by reciprocation thereof.

17. A tether cutting device comprising a body, a cable, means for rotatably mounting said body on said cable, means preventing said body from moving longitudinally of said cable, a severing element reciprocally extending into said body, said element having a cutting portion that projects outside and faces toward said body when said element is set and is reciprocated into said body when said element is tripped to cooperate shear-wise with said body, n means on said body causing said body to rotate as said body mounting cable is drawn through water to direct the cutting portion forward of said body and said body mounting cable, trigger means trippable by a tether between said cutting portion and said body, an explosion operated means responsive to tripping of said trigger means to retract said cutting portion of said element into said body, a beveled edge on said severing element extending forwardly of said body when said severing element is in retracted position, said longitudinal motion preventing means being sloped from said cable to the forward end of said body, whereby a first tether contacting said cable may ride over said longitudinal motion preventing means to the forward end of said body beneath said cutting portion and against said trigger, and a second tether contacted by said cable may ride over the beveled edge of said now retracted severing element to a further tether cutting device on said cable.

ROBERT TEMPLE, JR.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Great Britain 1914 

